Minneapolis Star Tribune: What started as a high school science fair project is the latest piece of evidence that global warming is affecting Lake Superior. Forrest Howk, now a freshman at the University of Wisconsin in Madison, studied 150 years of data in his hometown of Bayfield, Wis., and found that the harbor’s frozen season has shrunk from about 120 days to 80 days. The findings, published in the latest issue of Journal of Great Lakes Research, are consistent with recent studies showing that …